Minimally invasive surgery techniques have become increasingly popular due to the rapid healing and greater efficiency provided by such techniques. As these techniques have been developed, workers and surgeons have been faced with the problem of working in small places not visible by direct line of sight. Various tools have been designed to deal with this problem although none has been entirely satisfactory.
The standard surgical approach has been to make a large enough opening in an anatomically suitable location (which will heal without functional impairment) to establish direct visualization. Magnification can then be used to enlarge the target structure and various fiberoptic light delivery systems can be used to illuminate it. The actual surgical manipulation is then performed by direct manipulation of instruments held in the surgeons' hands.
Various scopes have been devised to see into deeper structures of the body such as the trachea, esophagus, rectum, and bladder. These scopes were rigid tubes of appropriate size to fit a naturally-occurring orifice. Some were equipped with magnifying lenses and others used removable telescopes with direct or even angled viewing capability. The advent of fiberoptic technology revolutionized endoscopic tools by allowing them to be flexible, thus opening the entire colon and upper gastrointestinal tract to visualization and making the majority of the bronchial tree accessible under topical anesthesia.
Early in the history of endoscopy, gynecologists developed laparoscopic tools for diagnostic and then therapeutic work in the pelvis. This involved placing a rigid tube with a TV camera into the abdomen through the umbilicus after distending the abdominal cavity with carbon dioxide. Through separate small ports additional instruments could be inserted for manipulating various structures and performing tasks such as tubal ligation. This basic concept has now been radically expanded to allow laparoscopic removal of the gallbladder, appendix, or even kidney. In the chest, lung biopsies, vagotomy, pericardial windows, and even lobectomy can be performed with video-assisted thoracic surgery ("VATS").
The common feature of these prior endoscopic surgical techniques is that a camera is inserted at one point and tools are inserted at two or more other points. Traditionally, one person operates the camera, another uses retracting or holding tools, and the surgeon's hands are then free to dissect, cut, excise, ligate, clip and otherwise manipulate the target structure. The instruments used have tended to be very long and thin in order to extend deep within the body without making a large incision. The control, operation, orientation and manipulation of the tool is accomplished at the proximal end of the shaft by the operator. It is much akin to using two-foot long chopsticks in each hand to manipulate grapes at the bottom of a bottle with vision limited to a two-dimensional TV image controlled by someone else.
Other workers in this field have developed or suggested various tools to deal with these problems, although the shortcomings of each has prevented widespread use.
For example, several references have suggested a single endoscopic surgery device containing a camera device, light delivery means, and one or more shafts for the insertion of tools, such as forceps or a scalpel. The purpose of these devices was to overcome the difficulties caused by poor visualization and the awkward operation caused by the Separation of control of the camera and the working tool. In each of these devices, the manipulation and orientation of tools has been accomplished at the proximal end of the shaft by inserting or retracting the tool in the shaft, and by mechanisms to control the bending of the shaft. A device incorporating a single telescope with a channel for a working tool is disclosed in U.S. Pat. No. 5,320,091, and a similar device incorporating a CCD chip imaging device is disclosed in U.S. Pat. No. 5,291,010. U.S. Pat. No. 4,674,501 has suggested a device that would allow rotation of a surgical tool, with detent means to fix the position of the tool for use. This device, however, would allow only circular rotation of the tool, and does not allow for manipulation and orientation of the tool at the distal end of the shaft. The above devices have been problematic because the visual contact with the surgery location has been inadequate, further compounded by difficulties in the manipulation and orientation of the tools. Moreover, the use of a single camera has resulted in a lack of depth perception.
In another reference, U.S. Pat. No. 5,368,015, a system is suggested that uses two cameras to provide a stereoscopic image for use in a traditional system that uses multiple insertions to insert the camera and tools.
The human vascular system, particularly the arterial side, is frequently afflicted by the obstructive consequences of atherosclerosis. This results in decrease of blood flow through the vessel and subsequent ischemia (lack of oxygen) in the tissues served by this vessel. The most-frequently involved vessels are the iliac branches of the aorta and their distal ramifications, the femoral arteries. The aorta itself can also be severely affected in some patients. The carotid arteries in the neck are another common area for this kind of obstructive disease which causes decreased blood flow to the brain with serious stroke as the ultimate threat.
The standard approach to this kind of obstructive disease has been endarterectomy (opening the vessel and removing the entire inner lining (intima) along with the intraluminal disease and then closing the outer lining of the vessel). When the abdominal aorta and/or iliac vessels are involved, a vascular bypass graft is often constructed as an alternative. Earlier stages of disease may be approached with angioplasty balloon catheters with or without endovascular stents. These techniques have depended on radiographic imaging modalities to localize the disease and the deployment of therapeutic devices. The hazard of embolization of atherosclerotic debris downstream in the treated vessel raises the risk of serious injury to the very structures one is trying to protect.
In a typical manual endarterectomy, an opening is made in the body to allow the surgeon access to the subject artery (or in some instances vein). The surgeon then makes a lateral incision in the artery wall, penetrating through the wall, the lining and the hardened matter within the artery. The surgeon then manually separates the artery wall from the hardened matter or plaque, ideally in such a way as to remove the matter in as large pieces as possible. Due to the consistency of the matter it is frequently possible to remove segments of hardened material as long as 10 cm through the opening. The artery is then sewn closed, and the body opening is likewise closed. The drawbacks to this process are that the patient is usually under general anesthesia, major trauma can be caused by the substantial body opening, only a limited portion of a limited number of arteries can be reached by direct incision, and the surgeon is unable to see the distal area where the plaque breaks.
Direct visualization of the inside of blood vessels has been made possible by the development of angioscopes--specialized flexible catheters with fiber optic equipment designed to provide a single camera-eye view of a vessel. There have also been contributions from intravascular ultrasound catheters which provide an internal view of a vessel with sound-wave technology. The ultrasound has the advantage of "seeing" through the blood stream, where the visible light spectrum devices demand a clear field. Neither of these devices is of any use in a totally occluded vessel.
It would therefore be of great advantage to have a new tool which would essentially treat the vascular tree as a body cavity of a specialized nature and transport appropriate tools through that tree to the point of obstruction and allow remote surgical treatment of the problem from the inside. The device would ideally allow for dissection of an endarterectomy plane, removal of debris, temporary occlusion of the vessel, irrigation, and suction, under stereoscopic visualization. In one embodiment, the working end of the remote dissector is modified to allow a port large enough for removal of bulky debris and the placement of two nodes at the tip, one for grabbing and or holding, the other for dissecting the tissue. Alternatively, the nodes could be incorporated into a smaller catheter to be passed through the outer catheter while the cameras, light sources, and irrigation equipment would be kept at the top along with a spatula and carbon dioxide insufflation nozzle. This brings the advantages of depth perception and control of instruments at the tip of the device to bear on the intravascular pathology.
It, therefore, has been found desirable to provide an endoscopic surgery device that allows for the manipulation and orientation of surgical tools at the distal end of the inserted shaft. It has also been found desirable to provide a camera for use in minimally invasive surgery, which solves the visual difficulties presented by prior devices, by providing stereoscopic vision through the use of two cameras placed at a proper distance for focus on the desired surgical area, combined in a single device with a surgical tool. It has further been found desirable to provide a single endoscopic surgery device incorporating stereoscopic vision in combination with a mechanism for allowing manipulation and orientation of surgical tools at the distal end of the device. It has further been found desirable to cofigure any of the devices for the conditions and requirements of intravascular surgery.